1. Field of the Invention
The present invention relates to a bending test apparatus for making a bending test on an elongated material or strip such as a bandsaw blade which has been welded into an endless shape. More particularly, the present invention pertains to a bending test apparatus for testing the bending strength of an elongated material such as a bandsaw blade by bending such a material.
2. Description of the Prior Art
It is often necessary to make a bending test on an elongated material or strip such as a bandsaw blade by bending such a material to test the strength of the same. Since bandsaw blades are welded into an endless shape or loop by welding ends of each bandsaw blade by means of a welding machine, a bending test is necessary to test the strength of a welded portion of a bandsaw blade to see the welding condition.
Heretofore, in order to see, for example, the welding condition for welding bandsaw blade into endless shapes, it has been customary to manually bend the welded portion of a bandsaw blade which has been welded to see the bending strength of the same from experience. Therefore, it has been inconvenient that the strength of the bandsaw blade allowable is swayed by the skill and experience of those who perform such tests, and it has been impossible to make an accurate bending test in this manner.
As an improved conventional manner, a bending test is performed by making a test ring having a radius of curvature and by manually pressing a test piece of elongated materials into such a curvature to see whether or not the test piece is broken. In this manner, however, it is necessary and troublesome to make many test rings for a variety of thicknesses and widths of elongated materials such as bandsaw blades. Furthermore, it is impossible in this manner to make an accurate bending test to see at what degree of bending the elongated material to be tested is broken.